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How to build a 4'x4' Ebb & Flow Bioponics / Peeponics System

This document is step by step instructions on building and using a 4’x4’ ebb & flow bioponic system. All steps were taken to be as frugal as possible without compromising integrity or quality. Links are provided for convenience, I have no association with the vendors. Prices and links are sure to change.

Why use Bioponics over other methods?


If you are choosing soil-less methods for growing plants then you can choose to do either hydroponics, aquaponics, vermiponics, bioponics, or peeponics. I'm sure there are other methods but hopefully I covered most of them. Each has their pros and cons. This document will not cover each method since a person can easily obtain this information on the web. I will be focusing on bioponics/peeponics. 

Bioponics or Peeponics unlike hydroponics, allows you to use your own fertilizer (urine) so you never have to buy costly nutrients.The system is completely close-loop so it does not require flushing or draining of the nutrient tank. Unlike hydroponics, you aren't dumping nutrient effluent on to your soil, or down the drain possibly causing pollution to your soil and waterways. Another difference is in how we view bacteria. Hydroponics requires sterility, which is counter-intuitive to what occurs in nature. While with peeponics, we encourage good bacterial growth, working with nature to help grow our food.

Comparing it to aquaponics, you don't have to worry if the ammonia levels rise too high since plants can tolerate much greater amounts than fish. PH fluctuations and temperature changes will do less damage to your system as well. Additionally, not everyone wants to have, keep, or eat fish. After you are done for the season with your system, you don't have to worry about what you are going to do with your fish. I personally only care about growing plants and find learning how to keep fish happy an unnecessary chore. Pumps are less likely to clog as opposed to aquaponics. This makes solid waste filtration completely unnecessary. So overall we have more flexibility with PH, temperature, ammonia, nitrite, and nitrate levels without worrying about fish deaths.

If we look at how plants grow naturally in soil, we can see how this type of system mimics it almost precisely. Imagine a small patch of soil in a forest. A grazing deer urinates on this patch of ground before running off. The billions of beneficial bacteria living in-between each particle of soil converts the ammonia in the urine to nitrites and finally nitrates. A bird plucks some fruit from a tree and a seed drops on to the soil. A gust of wind blows some soil debris on top of the seed. The seeds starts its journey to becoming a plant. Each intermittent rain shower allows the roots access to more nutrients and when the soil dries, it allows oxygen molecules access to the root system. Worms eat decaying plant matter and move through the soil, leaving behind its own excrement in the tunnels it creates, allowing roots more nutrients and oxygen. More animals urinate and defecate nearby, more plants die and slowly rot, all adding nutrients via bacterial actions. There are intermittent rain showers and dry times, combined with plenty of sunshine. The plant thrives and matures...

This is exactly what we do in bioponics. We have our rain showers (ebb & flow), we have urine (human aged urine), and nitrifying bacteria,  and "soil" (coconut coir & perlite), and sun (light system or sunlight). We can even add composting worms to the system and they will thrive and benefit our system. Bioponics/Peeponics mimics this natural process, but with human intelligence and precision. We supply the nutrients in the amounts that are ideal, we control the PH, and we control the rain.

Why use Ebb & Flow over other growing methods?

I chose Ebb & Flow over NFT, Constant Flow, Aeroponics, Constant Drip, etc. for the reasons that I will explain below.
They are relatively easy to build and maintain, so complexity is kept to a minimum. The material cost is low for the amount of plants that can be grown. In case of any type of failure (ie pump, timer, power ,etc.) the system should be fine until a replacement part is found.  Since the bed need to be flooded only a few times a day (possibly less with certain media), very little electricity is consumed, very little noise, odor, and humidity is created. Very little evaporation occurs. In case of power failure, there is a two-tote system that can be implemented cheaply in order to "manually" work the system. There is no need for aerating the reservoir since the plants get plenty of O2 when the growing bed drains.

Since we use individual pots in this system, different sized plants can be grown in the same system and each plant can be moved around to suit the needs of the grower without disturbing the other plants. Root systems are very delicate so this is very important.

This system is also very well suited for indoor growing due to the above reasons (odor, noise,etc.) and that the shape is perfect for most light systems (no light movers are necessary).


Dispelling the Myths


Not enough nitrification - I tested my system that was only up for 2 weeks and it had almost no ammonia and lots of nitrates. Even though the media is only getting flooded every hour or so for only 15 minutes, it is more than enough time for a massive amount of nitrification to occur, especially if you've chosen your media properly. 

Timers more prone to fail - I found timers to be very reliable and fairly cheap. I have timers that have been working for years in the most horrid conditions.

Root rot more likely to occur - If you use a medium like coconut coir mixed with perlite you will have a great combination of moisture retention and drainage. This will discourage root rot caused by water-logged plants.


Items List

Qty. 1 - 4’ x 4’ Hydroponic Tray (ebb/flow aka flood/drain)

Function: You will be growing your plants in this "tray". It needs to be sturdy and hold 15 gallons of water, media, and plants without breaking, collapsing or buckling.

Cost: $59.00

This is the most important part of the system but can also be the most cost prohibitive. Shipping can be very costly for this type of item (due to size), it is better to buy locally if possible. if you can't afford or find a flood and drain table, you can use any shallow large plastic tub or container such as a Rubbermaid watering trough, or an IBC tote cut in half. You can even build your own with a modified table and a pond liner.

Size: This depends on how much space you have for this unit, how much you want to grow, and how much your nutrient tank can hold. I found a 4'x4' tray can hold roughly 60 5" net pots.


Qty. 1 - Ebb & Flow bulkhead fittings -

Function: These fittings will provide the way that your hydroponic tray will be flooded and drained with nutrient water.

Cost: $8.95


Qty. 1 - 22-30 gallon Plastic Tote w/ Lid

Function: Will be the nutrient tank, holding the water that will flood and drain your hydroponic tray.

Requirements: The three most important aspects to getting a tote is to make sure it is not clear/translucent (so algae doesn't grow in it) and that the dimensions of the tote allows it to fit under the “table” that will be holding the 4'x4' tray. Lastly you also want to make sure that the quantity of water it can hold is sufficient for your Hydroponic tray. A 4'x4' tray when filled (using just 1 overflow extension fitting) holds approximately 15 gallons.

Costs: $15

Qty. 1 - ½” black poly tubing

Function: This will be the tubing needed for your pump to push liquid to your hydroponic tray.

Required Amount: You will need a length of the distance between where your pump sits (at the bottom of your nutrient tank) and the bottom of your hydroponic tray, in my case, less than 3' (36")

Approximate Costs: $1.00

Qty. 12” - ¾” black poly tubing - You will need the the length of the distance between the bottom of your hydroponioc tray and  $1.59

Qty. 1 - Hydroponic Pump - - $27.55

You can get smaller pumps, but I recommend nothing less than 120 GPH.

Qty. 1 - Timer - - $10.99
Any timer that allows 15 minutes increments is sufficient. No need for digital or anything fancy.

Qty. 25 - (Preferably Square) 1 gallon nursery pots - These pots can be obtained sometimes for free. You can find nursery pots at any Plant Nursery. You can use any size you wish but the system is setup to be able to handle roughly 25 square pots (1 gallon size). You can also get (5" or 6”) net pots instead. If you can’t find any pots, then the cheap alternative is to rummage through other people’s recycling and find plastic 1 quart (yogurt) containers, milk bottles, etc. You will have to punch a few small holes in the bottom to allow for the wicking action. - $00.00

Qty. - 1 - 11 pounds of Coconut Coir - - $15.95

Qty. 1 Bag - Perlite

Alternatives to Coconut Coir mixed with Perlite can be vermiculite, sand, gravel, hydroton, rockwool, shredded wood bark, etc. I find that coconut and perlite provide the best air to water ratio, a ton of nitrification (critical for what we are doing) and cheaper and lighter than most media.

Costs: $12.48

Link: -

If you are having problems with bugs or vermin, you can use hydroton (aka clay pebbles) as media. It's a little costlier but easy to clean and reusable.

Qty. 1 - Stand/Table/Surface

Function: We basically need an item that can hold the 4'x4' tray. You can use your imagination for this item. You can use an old table, a desk, a bunch of plastic crates, or even put it on the ground (you would have to make sure the plastic tote is lower so gravity can feed the nutrient water back to the reservoir). I use 8 crates (2 stacked on each side) and it holds the tray fine.

Costs: $00.00

Total cost of all items - $152.51 (plus shipping,taxes, etc.)




Place the 4x4 tray on top of a flat level stand/table/surface. Making sure the plastic tote clears it underneath. I recommend having the tray no higher than 2-3 feet from the ground. The higher it is off the ground, the harder it will be for the pump to push the liquid from the reservoir to the tray.


Drill two holes (1 ⅜” in diameter) in the bottom towards one side of the tray (if they aren’t there already) these should be right next to each other (a couple inches apart). Make sure these holes line up to the tote as this is where the liquid will be pumped up and draining back down so measure properly where you want these holes to be. You want these holes at the lowest part of the tray, meaning where it is indented.


Place the tote (with the lid) exactly where you want it to be situated once the setup is ready. I recommend that the tote stick out a little bit from under the tray so that we can have easier access to it, in case we have to do any type of clean-up or refilling.


Insert a pen through the top of the holes that were drilled into the tray and have it make a mark on the tote lid. We are marking the holes that we will drill into the lid of the tote.


Drill two holes in the lid of the tote where you marked it in step 4. For simplicity, you can use the same 1 ⅜” drill bit for all the holes.


Attach the two bulkhead fittings to the tray, making sure the barbed ends are coming out the bottom. Hand tighten it as much as possible. You will not need most of the extensions, just make sure one of the fittings is slightly taller than the other. The taller one is the overflow drain (it will have a bigger diameter), while the shorter one will be used to pump liquid from the reservoir and it will also drain back down once the pump turns off.


Attach the ½” poly tubing to the pump, place it in the bottom of the tote and run the tubing up through one of the holes in the lid and connect it to the bulkhead that is shorter.


Attach the ¾” poly tubing to the other bulkhead allowing it to go through the other hole in the tote lid.


Fill the tote with water. Make sure to fill it nearly to the top (the pump should be off right now).


Plug in the pump and make sure it pumps up to the tray, fills the tray evenly. If it is pooling more to one side or another, you may need to re-level the stand. It is important that we get even distribution of liquid in all parts of the tray.


Leave the pump on for 15 minutes to watch for leaks and to make sure that the overflow drain is working properly. The timer will be set for 15 minute ON increments so we want to make sure that it fills completely during that period of time and that it is draining back to the reservoir.


Lift up the lid on the reservoir and make sure there is enough water above the top of the pump so the pump is not running dry. The more water we have on top of the pump, the better. We don’t want to have to refill the reservoir too often if we can help it.


Turn off the pump and make sure the water drains completely.


Media Preparation


Fill a 5 gallon bucket halfway with a piece of compressed coconut coir (use a flathead screwdriver and a hammer to chisel a piece from the block) and fill the bucket with water. Let it soak for an hour. Fill the rest with perlite. Use your hands and mix the perlite and coconut coir making sure to have a nice even 50/50 mix breaking up any large pieces of coconut, add more water as needed.


Fill up each pot with the mix until it reaches the top. Do not try to compress it.


Place each filled pot in the 4x4 tray until there is no more room left.


Set the timer for on every 1 hour for 15 minutes. Do not set it to go on at night. Make sure the plugs do not sit lower than the unit for safety reasons. Plug in the pump to the timer.


Cycling the system


 Add 1-2 cups of aged (3-4 week old) urine. Wait a few hours and check the ammonia levels. We want a level of about 5ppm. Keep adding, waiting and checking until this occurs. Once we have 5ppm of ammonia, make a note of how much urine you added. This will be the daily amount you want to add to the system (however this will change as your system matures or more plants are added). 


Allow the system to cycle for a week or two. Then check ammonia and nitrate levels. We are looking for ammonia levels to first go up (when you first added the urine), then go down as the ammonia is converted to nitrates. (Testing for nitrites isn't really necessary). Once the ammonia levels drop down to below 1-2ppm, we can add more urine. This process may take 1-3 weeks. Once we have a good amount of nitrates (>20 ppm), it means the nitrification cycle is working properly and we can start adding plants or seeds.


Maintenance and upkeep

The main thing to watch every week (or more frequently in hot weather) is the level of the water in the reservoir, make sure to top it off as needed. We don’t ever want the pump to run dry, it will greatly reduce the life of the pump, possibly destroying the pump. Unlike hydroponics, we never need to dump and replace the nutrient water since we are not adding salts that will build up in the system. Although a once per season flush with regular water is not a bad idea just to clean out rotted roots, dead bugs, and other debris.

Check nitrate levels daily at first, if they fall below acceptable levels, add more urine. You may be able to do this weekly once you establish a pattern based on observation and recording your results.

PH checks should be done weekly as well. As long as the PH is within 5.9-7.0 we are okay. The nitrification process tends to be an acidic one, so you may need to buffer the PH by filling an empty pot with crushed oyster shell (easily obtained at amazon) or crushed egg shells and placing it in the tray. This will buffer the ph with every flow.

Every week, clean up the bulkhead fittings to prevent plant matter from clogging the fittings.

Every month, check and clean the pump to make sure that it is not getting clogged. Since there is nothing but water and urine going through the pump, you won’t have many issues with clogged pumps.

Harvest and trim plants as needed.

Check for bugs weekly. Bugs can easily be controlled using a fine mist sprayer mixed with a little bit of soap and water. Make sure not to miss the underside of the leaves as that is where a lot of bugs hide. Do not bother with diatomaceous earth since it only works in dry environments and will not work properly with an ebb & flow system.

Optional Indoor Setup


Hang a 400 watt Metal Halide/HPS (aka Sodium Vapor) Lamp from the ceiling using chains (at least 2-3 feet from the tallest plants so they don’t get burned). You can also use Fluorescents if you are growing only greens/low-light veggies although you may not be saving money on power consumption by doing so.


Have the lights turn on 16 hours and off 8 hours. You can set another timer to do this.


Do not spray anything while the Lights are on. If the MH/SV lamps gets wet, they can explode.


You may need a small fan to remove the heat from the lamp as well as to help the plants stem’s get stronger from the breeze.


 Updated: 12/15/2014 (two years after initial article, I've learned a lot, and included those lessons in the update)

Views: 9734


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Comment by Meir Lazar on December 1, 2014 at 4:19pm

Sorry for the delay in a response, I was growing groundnuts in there for awhile, and just recently moved the entire system, cleaned it, and am cycling it now. Here's a video I just took...

Comment by Butch Pornebo on September 15, 2014 at 7:31pm

do you have any recent pictures ?

thanks in advace

Comment by Butch Pornebo on September 15, 2014 at 7:30pm

"I actually use constant flow with gravel in my greenhouse and it works wonderfully."

meaning just keeping the bed flooded with an overflow drainage on the bed. dispense the use of bell siphon.

or let say piping around on all side and across of the grow bed with dripping holes plus draining at the bottom of the tank into the reservoir tank. will this work ?

does it require any aeration ? 

Comment by Michael Carlsen on January 23, 2014 at 3:27am

Thanks for your response.

So I have been utilizing grass powders that were grown in ORMUS rich soil which creates bioavailable rare earth minerals from everything like gold to iridium, that can influence the subtle energies in body and physiology.

So depending on what you intake it does carry over into your excrete, like when you feed duckweed and other natural things to fish and they carry that on in the nutrient makeup of their excrete as well. Uptaken by the plants in the end if soluble. As for amino acids and such they are utilized by the body as well and broken down by us into excrete too.  I wasnt implying that the plants needed the amino acids but to the end that depending on how healthy your diet is , you can choose it so it is more fully rounded when oxidized and nitrified?




Comment by Meir Lazar on January 22, 2014 at 6:49pm


I'm sure some of the others who are more knowledgeable will chime in, but perhaps I can offer my opinion on a few of your questions.

Urine can pass all kinds of things along including pharma, vitamins, etc. But bear in mind, just because these things are in the water doesn't mean the plants will draw them in so I don't know how much of an issue it would be. Just a guess, but I think a lab could analyse urine for any drug or chemicals.
The same goes for diseases.

Perhaps a botonist can comment on this? Do plants take in bacterium, virii, and/or drugs?

Any type of media or setup would work as long as the nutrient water has sufficient movement over enough media to cause nitrification. I actually use constant flow with gravel in my greenhouse and it works wonderfully.

Like i mentioned before, there are labs you can take your urine sample and have tested for all sorts of components but I would assume that it would fluctuate in it's composition every time you pee.

I wouldn't suggest eating rare earth minerals, or banana peel, however eating sufficient quantities of bio-available nutrients (like in vegetables, fruits, nuts, and seeds) would ensure that you maintain your health and you have a surplus to excrete and give to your plants. I could be wrong, but I don't think plants have essential amino acid (proteins that cannot be made) requirements like we do, they create their own from nitrogen and least that's what I heard.

I understand that it's hard to measure the potency of your urine, and this is problematic for some who want to be able to measure dosages with precision. The best advise I can think of is save the good stuff. Not the days where you were dehydrated, ate tons of sugary snacks, meats and junk food. IMHO.

Comment by Michael Carlsen on January 22, 2014 at 3:15pm

Ok so a more pointed set of questions for peeponics.

Do you think anything unnatural such as pharmaceuticals or disease could transfer from pee of a particular person to the system, and if that is so what would you use to test something like that? I dont use any pharma or have any disease, but for promoting the idea to others it would be great to say its ok or not depending on a person's circumstances.

Is it ok to run this system say with, vertical towers, or media bed in constant flow system?

I drink alot of water so I pee alot LOL, but would there be any circumstance that you could test your pee and determine what it is strong in and eat or drink accordingly to supplement certain aspects of nutrients you wish to break down. Kinda like a  bio incubation system that breaks down stuff with high potassium, or phosphorous, such as banana peel. Choose certain drinks with full amino acid profiles and that may have rare earth minerals that could be processed via nitrification to a bio available state?

Thanks for any response on this


Comment by Meir Lazar on January 21, 2014 at 6:01pm

Hi Michael, thanks for the comments! Most of the credit is to the other folks here, I just rip off what they do

But it is always nice to hear about other people's endeavours and if we help inspire, that makes all the typing worth the effort. 

Speaking of which, as I write this, I am looking at my ebb/flow bioponics system in my bedroom, and the dozens of daylilies and 20 canna lilies thriving in this system. I hope to grow them out until Spring, then transplant them to my recently acquired woods in West Virginia. Food forest in progress.

Comment by Michael Carlsen on January 21, 2014 at 10:36am

I love you guys so freaking much. LOL.

Since my initial dive into aquaponics I have been implementing bioponic ideas and concepts into my systems.

Here is some backround..

Garden and greenhouse story

Need to make a blog about it here someday. Anyhow I have been working with aquaponics for about 4 years now in maine. And I am now working towards a botany degree and still working on aquaponics LOL.  Regardless, Thank you all, Bob, Sylvia, Dave, Vlad, Meir, Nate,Tim, Tom, and everyone else for all the reverberated thoughts, resolving to universes of ideas, that have blossomed into great creations, including my own. Without you all I would certainly be no where.

Kind Regards,

Michael Carlsen

Comment by Vlad Jovanovic on November 22, 2012 at 2:26am

Cool. Keep us all posted. The struvite as a soil amendment, seemed to do quite well. Of coarse that's soil though. (I cant bring myself to spend the electricity growing indoors when it's summer outside, so I haven't done much else with it in that regard).

I did play around a bit to see how soluble it was in different conditions (different pH, temp, demi-water, my 'hard' tap water etc...) watched it form precipitates with calcium like any other phosphate based hydro fertilizer does...that kind of stuff. Looks promising...

At any rate, this doesn't really seem like something that will ever be, as you say "mainstream". And honestly, I kinda like that fact.

AP seems to have this "romantic" sort of element to it that the fish lend. Which is ok and all, and I am doing AP as well...but honesty that fish/romance comes at a price. Extra back up power supply equipment, extra equipment for solids filtration, more regular maintenance on the grow beds due to solids build up, more air equipment  larger pumps, more electricity, more heating. Not to mention the very unsustainable way in which most fish food is made (indiscriminate harvesting from the Oceans). The fish also very much limit the way in which you are allowed to deal with plant pests, even many organic remedies are a no-no, which further drives up you costs etc...If your not interested in the proteins the fish provide, it makes little sense (unless you are in a position to recoup all those costs with the sale of fish, which again seems like more hassle than it's worth for most people...proper licensing, and all the costs associated with food safety regulations inspections etc)...All that said, AP is still a great hobby, but pee-ponics may make more sense to certain people. In a way it is much more intimate (if not necessarily romantic), since you yourself are providing the nutrient input. You, by ingraining yourself into the nutrient cycle, are helping to close the loop and bring things that much closer to an idea of sustainability. This will certainly appeal to some folks, but their numbers, as well as their ilk, I imagine will be far from 'mainstream'. And that's fine...even preferable in a way. 

Comment by Meir Lazar on November 21, 2012 at 11:53am

Hey Vlad, that would be awesome. I've read all of your humonia-struvite work and I'm truly impressed with it. Even though I haven't done the process myself yet, mostly due to working on edible mushroom growing, I am still very interested to see how it performs.

Right now I will probably be focusing on plants that require mostly Nitrogen such as greens (napa cabbage, Sorrel, Watercress, chinese broccoli, chinese celery, choy sum, carrots, walking onions) and herbs (basil, dill, garlic chives, etc.) so I can establish reproducible results for these things. Then I will be switching to your method in the early spring time, when I will be using the beds in my greenhouse to grow tomatoes, peppers, cucumbers and melons.

The key to getting this to go mainstream, IMHO, is testing everything to the point where it becomes a science.  I expect within the next month or so, I will be writing another document on everything I've learned (on bioponics with greens) with lots of photos and videos on the progress. If you've tested struvite on fruiting plants, that would save me tons of work.

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